What is 2/5 plus 8/9?
2/5 plus 8/9 equals 58/45 (or 1 13/45 as a mixed number) (or 1.288889 in decimal form). Learn the step-by-step solution to add 2/5 and 8/9 using Least Common Denominator and simplification.
Exact Answer
2/5 + 8/9 = 58/45
Simplified Fraction
58/45
Mixed Number
1 13/45
Decimal Value
1.288889
Percentage
128.8889%
Step-by-Step Solution: 2/5 + 8/9
Step 1
Find the Least Common Denominator (LCD)
The denominators 5 and 9 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 5 × 9 = 45.
LCD(5, 9) = 45
Step 2
Convert to Equivalent Fractions with Common Denominator 45
Multiply the numerator and denominator of 2/5 by 9, and multiply the numerator and denominator of 8/9 by 5 so both fractions share the common base 45.
2 × 9/5 × 9 = 18/45 and 8 × 5/9 × 5 = 40/45
Step 3
Add the Numerators
Now add the numerators (18 + 40 = 58) and keep the common denominator 45 unchanged.
18 + 40/45 = 58/45
Step 4
Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 58 and 45 is 1, confirming that 58/45 cannot be reduced further—it is already in its simplest irreducible form.
58/45
Step 5
Convert Improper Fraction to a Mixed Number
Since the numerator (58) is greater than the denominator (45), divide 58 by 45: it goes in 1 whole time(s) with a remainder of 13, giving the mixed number 1 13/45.
58/45 = 113/45
Step 6
Decimal & Percentage Representation
Dividing the numerator 58 by denominator 45 produces a repeating decimal (approximately 1.288889, or 128.8889%).
58 ÷ 45 = 1.288889 (128.8889%)
Visual Representation
The diagram below illustrates 2/5 plus 8/9 visually:
+
=
Summary & Alternative Representations
| Property / Format | Value |
|---|---|
| Lowest Terms Fraction | 58/45 |
| Mixed Number Form | 1 13/45 |
| Decimal Form | 1.288889 |
| Percentage | 128.8889% |
Was this solution helpful?
Help us improve our free step-by-step tools
Frequently Asked Questions
What is 2/5 plus 8/9 as a fraction?
2/5 + 8/9 in simplest fraction form is 58/45 (or 1 13/45 as a mixed number).
What is 2/5 plus 8/9 as a decimal?
2/5 + 8/9 converted to a decimal is 1.288889.
What is 2/5 plus 8/9 as a percentage?
2/5 + 8/9 expressed as a percentage is 128.8889%.
How do you write 2/5 plus 8/9 as a mixed number?
Because the numerator is greater than the denominator, the improper fraction 58/45 can be written as the mixed number 1 13/45.
Does 2/5 plus 8/9 result in a terminating or repeating decimal?
It results in a repeating decimal (approximately 1.288889...) because the denominator contains prime factors other than 2 and 5.